Flashing relays



Sept. 30, 1958 R. J. LITTLE 2,854,547

FLASHING RELAYS Filed Aug. 30, 1954 4 Sheets-Sheet 1 FIG.|.

LCI

F|G.4. 72 75 77 e9 IN V EN TOR.

HIS ATTORNEY Sept. 30, 1958 R. J. LITTLE 2,854,547

- FLASHING RELAYS Filed Aug. 30, 1954 4 Sheets-Sheet 2 :p/ta INVENTOR. s3

R.J.L|TTLE HIS ATTORNEY Sept. 30, 1958 R. J. LITTLE FLASHING RELAYS 4Sheets-Sheet 3 Filed Aug. 30, 1954 INVENTOR.

R.J.L|TTLE HIS ATTORNEY Sept. 30, 1958 R. J. LITTLE 2,854,547

- FLASHING RELAYS Filed Aug. 30, 1954 4 Sheets-Sheet 4 FIGS.

47 LCI FIG/9.

IN VEN TOR.

HIS ATTORNEY United States .1: tent FLASHTNG RELAYS Robert J. Little,Rochester, N. Y., assignor to General Railway Signal Company, Rochester,N. Y.

Application August 30, 1954, Serial No. 453,001

9 Claims. (Cl. Nil-93) This invention relates to direct current relaysof the oscillating armature type particularly adapted to flash signallights at a railroad highway crossing upon the approach of a train. Itmore particularly pertains to the correlation of a novel contactstructure with a pivoted armature in such a way that suitable timing ofthe relay armature operation and the flashing of the signal lights isaccomplished in a positive and safe manner in accordance with rigidsafety requirements.

A primary object of the invention is the provision of a set of specialcontacts to permit automatic energization of one or the other of therelay coils for alternate periods of time so long as the main energizingcircuit is closed, as for instance, by the presence of a train in thehighway crossing track section. These contacts are held closed in one orthe other of two positions by means of permanent magnets until movementof the relay armature occurs, at which time the closed contactconnection is forceably broken and moved to a reverse contactingposition by a snap action movement.

Another object of the invention is the provision of nonbounce type oflamp control contact assemblies wherein two separate contact groupscooperate to center the pivoted armature in the absence of energizingcurrent and yet provide contacts which are closed in such centerpositions with normal contact pressures. This provides positive controlof the associated warning lamps even though the relay should fail tooperate.

Further objects, purposes and characteristic features of the inventionwill be apparent as the description progresses and by reference to theaccompanying drawings.

In describing the invention in detail, reference will be made to theaccompanying drawings, in which like parts are referred to by likereference characters, and in which:

Fig. 1 is a front elevation view of a flashing relay constructed inaccordance with the present invention;

Fig. 2 is a side elevation view partly in section showing relaystructure and the lamp control contacts;

Fig. 3 is an enlarged side elevation view of the special coil controlcontacts;

Fig. 4 is a sectional view taken on the line 44 of Fig. 3 showing themovable contact of the coil control contacts;

Fig. 5 is a sectional view taken on the line 5--5 of Fig. 3 showing astationary contact of the coil control contacts which each carry apermanent magnet;

Fig. 6 is a sectional view taken on the line 66 of Fig. 3 showing themeans of mounting the pusher on the biasing springs of the coil controlcontact structure;

Fig. 7 is a perspective view of the relay core structure shown in Figs.1 and 2;

Fig. 8 is a diagrammatic view shown more for the purpose of illustratingthe operation of the relay; and

Fig. 9 is an enlarged sectional view of the armature stop screw.

Referring now more particularly to Figs. 1, 2, 3 and 7,

the usual back plate or base 11 of the relay is constructed of moldedinsulating material. This back plate 11 acts as a mounting for the relayand also supports the various relay elements, such as the contactstructures LCl, LCZ and CC, the cores 12, 13 and 14, and the rearbearing pin 15 for the contact operating shaft 16. These cores 1'2, 13and 14 are magnetically tied together by a back yoke 17 which isinserted between the ends of the cores and the relay back plate. Largescrews 18, one for each core, are passed through the back plate 11 andthe yoke 31'? and threaded into the cores 12, 13 and 14. The screws 18are drawn up tightly to provide a rigid support for the cores 12, 13 and14 and also to provide a proper magnetic connection between the cores12, 13 and 14 and the back yoke 17.

The cores 12, 13 and 14 are each provided with an enlarged pole shoe,such as 19, 20 and 21. These pole shoes are properly positioned withrespect to the armature 22 and held in place by a non-magnetic faceplate 23 which is fastened to the pole shoes 19 and 20 by rivets 24 andthe pole shoe 21 by screws 25. The armature 22 is adapted to oscillateback and forth between the pole shoes 19 and 20 and is suspended from,and fastened to, the shaft 16. This shaft 16 is mounted to oscillate ontwo pinion type bearings, the rear bearing 15 being located in the relayback plate 11 and the front bearing 26 being located in a bracket 27which is mounted on the front of face plate 23 by means of screws 28.These pinion type bearings 15 and 26 are screw threaded and areadjustably mounted and held in position by lock nuts 29.

As it can be seen with reference to Fig. 1, the pole shoes 19, 2t) and21 are so positioned that the armature 22 in its neutral position willhang directly above pole shoe 21 and between the pole shoes 19 and 20,leaving an air-gap on either side. The amount of the air-gap on eitherside is preset and maintained by means of adjustable stop screws Stl.The bottom face of the armature 22 and the top face of the lower poleshoe 21 are arcuate in shape to correspond to the swing of the armature22, the air-gap therebetween being predetermined and non-adjustable.

The lower head part of the armature 22 is provided with a cored hole 31in its center to reduce the size of the mass and provide a more directpath for the passage of fiux therethrough. The core 14 is provided witha cylindrical copper slug 32 to retard the flow of flux therethro-ughfor reasons explained hereinafter. The cores 12 and 13 are provided withthe usual energizing windings or coils, such as 33 and 34.

As previously mentioned, the armature 22 hangs in a vertical positionand is fastened to a horizontal shaft 16, as by a pin 35, so as to swingbetween the two pole shoes 19 and 20. Fastened to the shaft 16 in ahorizontal plane and at right angles to the shaft 16, is a contactoperating arm 36. This is conveniently done by passing the arm 36through a hole in the shaft 16 and welding the two parts together. Thisprovides a contact operating arm which reflects the movement of thearmature 22 and this movement is transmitted to the pushers 37, 3S and39 of their respective contact groups LCl, LCZ and CC. The pushers 37and 38 are biased toward the flat ends 40 of the operating arm 36;whereas, the pusher 39 is connected to it, so that they are all in aposition to be operated by the arm 36 as will be fully explainedhereinafter.

As referred to above, the air-gap on either side of the armature 22between the pole shoes 19 and 20 is adjustable by means of a stop screw30. When the armature 22 is attracted to one of the pole shoes, either19 or 20, the tip of the stop screw 30 will come in contact with anon-magnetic hardened metal residual pin 111 located in armature 22. Inorder to reduce the shock and damage to these metal parts caused by theconsistent pounding and still maintain a fixed air-gap, the tips of thestop screws are provided with an insert 112 made of Formica or suchother materials as Phenolic, etc.

The insert 112 (see Fig. 9) is made with a reduced portion on itscontact tip, thus forming a shoulder as at 113. The stop bolt 30 isprovided with a bored hole having a reduced portion 114, thus forming ashoulder as at 115. When the insert 112 is placed in the hole in thestop bolt 30, its bottom enlarged portion will rest against the shoulder115. The end of the stop bolt 3 is then spun over the shoulder 113 asshown, to hold the insert 112 in place.

When assembled, there is just enough clearance around the insert 112 toform a loose fit. This creates a socalled air pocket behind the insert112 in the innermost reduced portion 114- of the hole in the stop bolt3th When the insert part 112 of the stop bolt 30 is struck by theresidual pin 111 of the armature 22 upon movement of said armature, thecombination of the air pocket and the resiliency of the insert 112combine to absorb the impact of the armature 22. After adjustment of theair-gap, the stop screw 30 is locked in place by a nut 116.

Referring now more particularly to the detail construction of thecontact group assemblies, the lamp control groups LCl and LCZ are eachcomprised of a molded insulation block 41 having the contact fingers andbiasing springs molded therein during manufacture. The two biasingspring 42 and 43 extend outwardly at right angles from the supportingblock 4-1 and carry the contact operating pusher, such as 37 or 38. Thepusher 3a is mounted on hearing pins 45 and held in place by clips 46.These bearing pins 45 and clips 46 are situated in a slot 47 formed inthe biasing springs 42 and 43, similar to the manner shown in Fig. 6 inconnection with the mounting of pusher 39. The pusher 33 passes withinthe slot 47, the clips 46 maintaining the pusher 33 in position after ithas been moved forward to rest upon the bearing pins 45.

Each of the contact assemblies LCl and LC2 has a complement of twocontact groups, the upper group comprising a movable front contactfinger 47, an intermediate stationary contact finger 43 and a movableback contact finger 49. Likewise, the lower group comprises similarcontact fingers t), 51 and 52. The pusher 38 is pro vided with fourslots to form shoulders 53, 54, 55 and 56, these shoulders cooperatingwith the contact fingers 47, 49, 50 and 52 as the pusher 38 assumesdifferent positions. During assembly, the contact fingers 47 and 49 arebiased to bear against the stationary contact-finger 48 and the contactfingers 5t and 52 are biased to bear against the stationary contactfinger 51. Also the biasing springs 42 and 43 are adjusted to hold thebottom biasing spring against a stop retaining arm 57, in which positionthe bottom of the pusher 38 will be located ator very near a contactingpoint with the fiat portion 40 of the contact operating arm as, theshoulder 54 will be bearing against the contact finger 49 and theshoulder 56 will be hearing against the contact finger 5'2.

It should be noted at this point that the downward pressure exerted bythe biasing springs 52 and 43 must be great enough to overcome the biasof contact springs 49 and 52 as well as hold the pusher 38 down inposition next to the fiat portion 40 of the contact operating arm 36. Itis believed that with reference to the drawings and the descriptionalready given, it can be seen that the relay armature 22 will benormally biased to its center position by reason of its own weight anddue to the fact that the push'ers 37 and 38 of the contact groups LCD.and LC2 are bearing against the flat portions 4ft of the cor.- tactoperating arm 36, one on either side of center. Upon movement of thearmature 22 to the right or left, the contact operating arm will raiseeither one or the other of the pushers 37 or 38, causing the shoulders55 and 55 to bear against the front contact fingers 4'7 and Stl, thusbreaking contact with the stationary contact fingers 43 and 51. With thepushers 37 or 38 in their upper positions, shoulders 54 and 56 will bemoved away from contact fingers 49 and 52, allowing them to assume theirbiased positions against stationary contacts 48 and 51. In other words,the function of the pusher is to force a break in a given pair ofcontacts which are normally made by reason of their own bias.

The coil control contact group assembly CC comprises the usual moldedinsulation block 60 having contact fingers and pusher supporting springsmolded therein in the usual way. The pusher supporting springs 61 and asare made of a thin metal resilient material and are cut out as shown at63 to further increase their flexibility. The pusher 3% is hung andsupported at the outer ends of these springs 61 and 62 by the usualbearing pin 45 and clip 4-6 as explained in connection with the lampcontrol contact assemblies LC1 and LC2. The bottom end of the pusher isforked as shown at 67 to fit over the fiat portion 40 of the contactoperating arm 36 so that the pusher 39 will operate up and down incorrespondence with the back and forth movement of the armature 22.

The contact group comprises a front stationary contact finger as, amovable contact finger as and a back stationary contact finger 70. Themovable contact finger 69 is provided with two spaced resilient metaltips '72 and 3; and two iron washers 75 and 76, one of each on eitherside. A large rivet 77 of suitable contacting material, such as silver,is used to hold the assembly together. This movable contact finger 65 isalso cut out as shown at 71 to increase its flexibility. The frontcontact 68 is pro vided with a permanent magnet PMl preferably of verystrong flux, such as Alnico No. 5 or similar quality material. Thismagnet PMl is held to the contact finger 68 by means of a bolt and nut78, the head of the bolt having a piece of silver 79 attached thereto.Similarly, the back contact 70 i provided with a permanent magnet PMZwhich is held in place by a nut and bolt 80 which has a silver contact81 attached to its head.

These permanent magnets PM1 and PM2 are recessed as shown at 74 toreceive the full width of their respective contact fingers 68 and '76 sothat when bolted together, the permanent magnets are prevented fromturning. Also, each permanent magnet PMl and PMZ is provided with atransverse groove 53 in its face portion to definitely establishopposite poles and facilitate the flow of flux therethrough. Acounterbore 59 allows the heads of the bolts '78 and 80 to becountersunk below the face surface of the magnets.

The pusher 39 is recessed to form two shoulders 82 and 83 as shown. Theresilient tips 72 and 73 of contact finger 69 extend into this recessand are so positioned that a downward movement of the pusher 3-9 willcause the shoulder 82 to contact the tip '72 and an upward movement ofthe pusher 35" (assuming the contact 65 to be in its back contactposition) willcause the shoulder 33 to contact the tip 73.

It should be noted that the bolts 78 and 8t and the rivet 77 not onlyserve to hold the various parts together but also serve as conductorsfor the electrical current through the contacts and provide an air-gapmeans to prevent the permanent magnets of contacts 68 and 76) fromcoming into actual contact with the iron washers of contact 69. As amatter of convenience for plug coupling purpor' .52. the various contactfingers above mentioned all extend through their supporting blocks andare shaped as shown at 84 and 85 to facilitate the reception of plugconnector in the usual way.

With particular reference to'Fig. 3, the position of movable contactfinger 69 shown in contact with stationary contact finger 62 is assumedto be the last operated po ition of the relay, it being understood thateither the front or the back contact is always closed in the normaldeenergized position of the relay. In this position, the next movementof movable contact 69 would occur when the pusher 39 is moved downward.

Assuming now that coil 33 on the left was to become energized, relayarmature 22 would move to the left and the right hand end of contactoperating arm 36 would pull the pusher 39 downward. As the movement ofthe pusher 39 starts downward, the shoulder 82 will bear against theresilient tip 72 and tend to force contact finger 69 downward. However,the magnetic pull between permanent magnet PMl and iron washer 75 is ofsuch strength that it would hold contacts 68 and 69 in a closed positionuntil such a time as the pusher 39 builds up enough pressure against theresilient tip 72 to overcome this magnetic pull. The factors are sochosen and the parts so proportioned that the contact breaking pointcomes at a time when the resilient tip 72 is bent down until it is justshort of touching the main contact finger 69. The built up pressure inthe combination tip 72 and finger 69 will then break the hold of thepermanent magnet PM1 and the contact finger 69 will start movingdownward. As the iron washer 75 starts to leave the magnetic field thepermanent magnet PMl, the trapped pressure in the resilient contact tip72 will show its effect and snap the contact 69 towards the back contactfinger '70. As the movable contact finger 69 passes its mid-position,the iron washer 76 will come into the magnetic field of permanent magnetPM2 and the magnetic pull of this magnet will complete the snap actionmovement of movable contact finger 69 and cause it to make connectionwith its back contact member 70 through the rivet 77 and bolt 80. Upon areverse movement of the armature 22 which would cause an upward movementof the pusher 39, the shoulder 83 would contact the resilient tip 73shortly after the armature 22 passes through its mid-position andmovable contact finger 69 would be moved back to its front contactposition in a manner similar to that described above.

Referring now more particularly to Fig. 8, there has been shown asimplified operating circuit in connection with a diagrammatic showingof the operating parts of the relay, such as the core structure, thearmature 22, contact operating arm 36, the two lamp control contactassemblies LC1 and LC2 and the coil control contact assembly CC.

It is assumed that the line control relay XR is energized because of theabsence of a train in the usual highway crossing track section, thus allenergy is cut off from the flashing relay and its associated lampcontrol and coil control contact LC1, LC2 and CC. The relay armature 22is now biased to its center position by reason of the biased pushers 37and 38 as previously explained. With the relay armature 22 in its centerposition, the

front contacts 47 of the lamp control contact groups LCl and LC2 arebiased to a closed position and the movable contact 69 of the coilcontrol contact group CC is held closed against the front contact 68 bythe magnetic pull of the permanent magnet PM1, since this happens to bethe last operated position of this contact group CC.

Upon entrance of a train into the usual highway cross ing controlsection (not shown), relay XR is deenergized, causing its back contacts86, 87 and 88 to be closed. With contact 88 in its back position, acircuit is established to light the lamp E1, which is assumed to be oneof the flashing lamps to warn highway trafirc approaching a railroadcrossing from an easterly direction. This circuit may be traced from theside of a source of current to the contact 88, wires 89 and 90, contactfingers 4-7 and 48 of the lamp control contact group LC1, wire 91,filament of the lamp E1 and through a suitable voltage limiting resistorto the side of the source of current. Similarly, with the contact 87 inits back position, the westbound highway trafiic warning lamp W1 islighted by a closed circuit traced from to the con- 6 tact 87, wires 92and 93 to contact fingers 47 and 48 of the lamp control contact groupLC2, wire 94, filament of the lamp W1 etc. to

Also, with contact 86 of the control relay XR in its back position, anenergizing circuit for the flashing relay is established. As previouslymentioned, movable contact finger 69 of the coil control contact groupCC always remains in one or the other of its closed positions after theflashing relay has ceased functioning after its last operation. It hasbeen assumed tht it has stopped in its front contact position in contactwith stationary contact finger 68, and is held there by the permanentmagnet PMl. With the coil control movable contact 69 in this position,the energizing circuit will supply current to the winding 33 through acircuit which may be traced from the side of battery B, wire 95, backcontact 86 of relay XR, wires 96 and 97, winding 33 on the core 12,wires 98 and 99, contacts 69 and 68 of the coil control contact groupCC, wires 100 and 101 back to the negative side of the battery B.

With winding 33 energized, flux will begin to flow in the direction ofthe dotted arrows A1 through the core 12, yoke 17, core 13, pole shoe21, armature 22, pole shoe 19 and back to core 12. As previouslymentioned, core 13 is provided with a short circuited winding or copperslug 32 so that the building up of flux in the magnetic structure justdescribed is retarded for a short interval of time. When suflicient fluxis built up in this magnetic circuit the armature 22 will be attractedto the pole shoe 19, an air-gap being maintained by reason of theresidual screw or pin 30.

Upon movement of the armature 22 to the left towards pole shoe 19, theshaft 16 and its associated contact operating arm 36 will turn in aclockwise direction, causing the left-hand portion of arm 36 to rise andthe right-hand portion of arm 36 to drop. The upward movement of thisleft hand portion of arm 36 will force the pusher 37 upward, causingcontact finger 47 to break with contact finger 48 and allowing contactfinger 49 to make with contact finger 48 due to its own bias. When thishappens, flashing lamp E1 will be extinguishe. and flashing lamp E2 willbe lighted by a circuit traced as follows: from to back contact 88 ofrelay XR, wires 89 and 102, filament of the lamp E2, wire 91, contacts48 and 49 of the lamp control contact group LC1, wire 183 and. throughthe voltage limitin resistor to At the same time the left hand portionof contact operating arm 36 moves upward, it is obvious that the righthand portion will move downward. This downward movement of the righthand portion of the arm 36 does not disturb the pusher 38 of the lampcontrol contact group LC2 as the biasing spring 43 is against the stop57 and consequently, no movement of the pusher 38 can take place as thearm 36 moves away from it. As a result, the flashing lamp W1 will remainlighted during this interval so that a warning light will be displayedfacing the highway trafiic approaching from both directions. However,this downward movement of the right hand portion of the arm 36 will movethe pusher 39 of the coil control contact group CC downward and in sodoing the pusher 39 will force a break between contact fingers 69 and 68and allow a contact to be made between contact fingers 69 and 70 aspreviously described, the permanent magnet PM2 attracting and holdingthe iron washer 76 of contact finger 69.

When this change takes place, a new circuit is established and theenergizing current for winding 33 is cut off, and transferred to thewinding 34 on the right hand core 14. This circuit may be traced asfollows: from the side of battery B, wire 95, back contact 86 of relayXR, wires 96 and 104, contact fingers 70 and 69 of the coil controlcontact group CC, wires 99 and 105, winding 34 on the core 14 and wires106 and 101 back to the side of the battery B. Upon deenergization ofthe winding 33, the armature 22 does not immediately swing to itsvertical center position even though the bias of pusher 37 tends to makeit do so. This is because the highpercentage of flux built up in themagnetic field including the core 12, and previously described, willtake a larger interval of time to decay than would be the case if thecopper slug 32 were not present. While this flux decay in the core 12 istaking place, with the winding 34 now energized the flux will bebuilding up in a new magnetic field including the core 14, pole shoe 20,armature 22, pole shoe 21, core 13 and yoke 17, as indicated by thedotted arrows A2.

As the flux continues to decay in core 12 and build up in core 14 untilsuch a time as they are about equal, the downward bias of pusher 37 ofthe lamp control contact group LCll against the arm 36 will begin toprevail and the armature 22 will begin to move to its center verticalposition. At this stage of the operation the pusher 37 will have forcedthe contact finger to make contact with contact finger 8, due to its ownbias. This change will now extinguish flashing lamp E2 and again lightflashing lamp Eli through a circuit which has been previously traced,thus completing a flashing cycle between the lamps E1 and E2.

As the armature 22 moves toward its center vertical position, the fiuxin the new magnetic path including core 14 will have increasedsufiicient enough to attract the armature 22 to the pole shoe 20,thereby turning the shaft 16 and the contact operating arm 36 in acounterclockwise position. In this position, the left hand portion ofarm 36 will move downward and the right hand portion will move upward.The downward movement of the left hand portion of the arm as will noteffect the pusher 37 of the lamp control contact group LCll and the lampEll will remain lighted. However, the upward movement of the right handportion of the arm 36 will raise both pushers 33 and 39. The upwardmovement of pusher 38 of the lamp control contact group LCZ will causecontact finger 47 to break from contact finger 48 and allow contactfinger 49 to make contact with contact finger 48 in a manner similar tothat described in connection with the operation of lamp control contactgroup LCl. In this position, lamp W1 will be extinguished and lamp W2will be lighted, the new circuit cutting off energy to lamp W1 andtransferring it to lamp W2 as follows: from to back contact 87, wires 92and 107, filament of lamp W2, wire 94, contact fingers 48 and 49, Wire1% to the voltage limiting resistor and Here again, there will be atleast one warning light, either E1 or W2, displayed to highway trafiicapproaching the.railroad crossing from either direction.

At the same time pusher 38 moves upward, pusher 39 will also moveupward, and cause a break between con tact fingers 69 and 7t and makecontact between contact fingers 69 and 63, thus establishing theoriginal circuit previously described. It will now be obvious that theenergizing current is cut oif from winding 34 and again transferredover'to winding 33. Thus, the building up of flux in core 1'2. and thedecaying of flux in core 14 must take place before another shift of therelay armature 22 occurs, the same procedure taking place as previouslydescribed in connection with a counterclockwise movement of the armature22.

From the foregoing description and with reference to the drawings, itwill be understood that once energy is supplied to the flashing relay,as for example as illustrated by the dropping of relay XR due to thepresence of a train in the highway crossing track section associatedwith the highway crossing, the flashing relay armature 22 will continueto reverse its direction of movement at certain spaced time intervalsand thereby cause a flashing of the lamps Ell-E2 and Wit-W2; until sucha time as the tran proceeds out of the highway crossing track section,whereupon the relay XR will become energized cut off current to theflashing relay. The spaced time interval recommended in accordance withaccepted standards is about 45 to 50 times per minute and the values ofthe windings 33 and 34 and the copper slug 32 as well as the contactfinger adjustments are so chosen that the correct results are obtained.

For instance, it will be noted that the space between the end of contactfinger 47 and the shoulder 53 of the pusher 38 of the lamp controlcontact group LCl must of necessity be smaller than the distance betweenthe contact surfaces of contact finger 4-9 when in a position as snownin Fig. 2, because contact fingers 47 and 48 we ole rly broken beforecontact fingers 48 and 49 are made. This prevents a complete shorting ofboth lamps but does create a short dark interval between theextinguishing of one lamp and the lighting of the other lamp, thusproviding a flashing effect of the lamps with either one or the other ofthe lamps lighted up during most of the time interval between changes.

Also, the fact that both of the contact fingers 47 and 49 are biased toa closed position with respect to stationary contact 4-8 guarantees thateither one or the other of the lamps will light up during the presenceof a train into the highway crossing control track section, because thepusher 37 can only hold one contact open at a time, either one or theother remaining closed dependent upon the position of the relay armature22. Consequently, if the flashing relay armature 23 failed to operatefrom its center position or became stuck in either extreme operatedposition for some reason or other, there would always be at least oneflashing lamp lighted steadily to warn approaching highway traffic.Furthermore, if any one of the contact fingers 47, 43 or 49 shouldaccidentally be broken or burned out, or fail to conduct current for anyother reason, the two sets of lamps E1E2 and W1WZ would become coupledup in series circuits and each would light up to show a somewhat dimmerlight, but still act as a warning to approaching highway traffic.

It should also be noted that the bias of the pusher 37 to a downwardposition by reason of biasing springs 42 and 43 must be sufiicient toovercome the bias of contact fingers 49 and 52 as well as return thearmature 22 to its center position, the stop arm 57 preventing anyfurther downward movement of the pusher 37. The same is true withrespect to the lamp control contact group LCZ.

As previously mentioned, the coil control contact group CC has itspusher 39 interlocked with the contact operating arm 36 so that movementof the armature 22 in either direction will affect the movement of themovable contact finger 69. In the position shown in enlarged Fig. 3, itis assumed that the armature 22 has just operated the pusher 39 and itsassociated movable contact 69 to an upward position and the armature 22has returned to its center position and is now in position to move thepusher 39 and the contact 69 to a downward position.

it will be noted that there is a small gap between the upper shoulder 82of the pusher 39 and the resilient tip 72 of Contact finger 63 and amuch larger gap between the lower shoulder 83 and the resilient contacttip 73. in this position, it will be obvious that the lower gap must belarger because it must equal the space of the upper gap plus thedistance the pusher 39' will move downward on its next operation. Afterthe pusher 39 has moved downward in response to the next operation ofthe armature 22, the operated contact finger 69 will position itself sothat the small gap will be between contact tip 73; and shoulder whereasthe large gap will be between contact tip 72 and shoulder 82. It standsto reason that the airgap between the movable contact finger 69 andstationary contact finger 70, as an example, must be so proportioned sothat when the pusher 39 is moved downward as just described above, thepermanent magnet P112 will hold the silver rivet head 7 tightly againstthe silver tip 81 on the head of bolt 83, leaving a slight airgapbetween the permanent magnet PMZ and the iron washer 76 and also leavinga slight airgap between the contact tip 73 and the shoulder 83.

As previously described, i-pon movement of the pusher 39 to a downwardposition from its position as shown in Fig. 3, the shoulder 82, wouldbear against the resilient contact tip 72, thereby forcing it downwardagainst the pull of the permanent magnet PMl. Under ordinarycircumstances, the downward force being built up in the contact tip 72and its associated contact finger 69 while the pusher 39 is movingdownward would be sufficient to overcome the pull of the permanentmagnet El /ill at a point just before the contact tip 72 reaches theextreme end of the movable contact finger 69, thus causing operation ofthe movable contact to its back position wherein it contacts stationarycontact 7%. However, in the event that contact fingers 68 and 69 becomestuck together, such as by the arcing and burning of its silver contactelements 77 and 79, there is still enough armature movement left so thatthe further movement downward of the pusher 39 would cause contact tip72 to actually bear against the extreme end of the movable contactfinger 69 and force a break between the contacting elements 77 and '79.

With reference again to Fig. 8, it will be seen that the coil controlcircuit has been provided with the usual resistance Ml? and condenser110 which is wired across one of the coil windings, such as 33, tominimize the arcing across the above mentioned contact elements, such as'77 and 79 or 77 and 81. This incidentally also minimizes theinterference which is caused by the arcing and transmitted to radioreceivers which may be located in the immediate vicinity of the highwaycrossing.

It is believed that the invention shown and disclosed herein presents anew and novel way of providing flashing highway crossing signal lightswhich afiord better protection and safety. It should also be understoodthat the self-closing biased type of non-bounce contacts provided forthe lamp controls are more durable and capable of handling highervoltages without contact arcing and burning. Also, the coil controlcontact structure provides a positive quick snap action control wherebyenergy is transferred from one coil winding to the other in a minimum oftime even though the relay core structure is purposely constructed tomake it slow acting to provide proper time intervals between reversal ofarmature operations.

It is also desired to be understood that even though these novel contactstructures are particularly desirable in a flashing relay of the typeshown and described, they could be very easily adapted for use in othertypes of relays and circuit controlling devices.

Having shown and described one form of the invention, it should beunderstood that various adaptations and deviations in the structurescould be made without departing from the spirit of the invention or thescope of the appending claims.

What I claim is:

1. In a relay organization, an electromagnetic core structure with acooperating armature operable to either of two extreme positions byselective energization of windings on said core structure, spring meansacting to normally bias said armature to a mid-position, two fixedcontact fingers, a pair of movable contact fingers associated with eachof said fixed contact fingers, the fingers of each pair being located onopposite sides of such fixed contact finger and biased toward it, acontact operator for each pair of said movable contact fingers and whichis operably connected to said armature, each such contact operatoracting to hold said movable fingers of its pair at spaced points awayfrom each other and each away from its respective fixed contact for oneextreme position or the other of said armature but allowing one of saidmovable contact fingers of each pair to make contact with its respectivefixed contact While said armature is in a mid-position and one of itsextreme positions.

2. In a relay organization, a contact block of insulating material, arelatively rigid contact finger mounted on said block, two relatitaalyflexible movable contact fingers mounted on said contact block onopposite sides f said fixed contact finger and biased toward it with apredetermined pressure, a contact operator of insulating material, twospring supports for said contact operator mounted on said contact blockfor permitting limited movement of said contact operator in a particularplane, said contact operator having a spacer portion located idingportions of said two movable contact fingers to hold them away from eachother for a distance slightly greater than the thickness of said fixedcontact finger located between them, said spring supports having apermanent deformation causing them to bias said contact operator in aparticular direction causing its spacer portion to hold one of saidmovable contact fingers away from said fixed contact finger but allowingthe other of said movable contact fingers to rest against said movablecontact finger wholly free of any connection with said contact operator,a stop member for limiting the movement in said particular plane of saidcontact operator by the bias of its supporting springs, and electromagnetic means efiective when energized for moving said contact operator ina direction opposite to its bias for permitting the opposite movablecontact finger to make contact with said fixed contact finger inaccordance with its bias independently of any connection wtih saidoperator but causing said spacer portion to move said one movablecontact finger away from said fixed contact finger.

3. in a relay organization, two contact structures, each comprising ablock of insulating material, a relatively rigid contact finger mountedon said block, two relatively flexible movable contact fingers mountedon said contact block on opposite sides of said fixed contact finger andbiased toward it with a predetermined pressure, a contact operator ofinsulating material, two spring supports for said contact operatormounted on said contact block for permitting limited movement of saidcontact operator in a particular plane, said contact operator having aspacer portion located between extending portions of said two movablecontact fingers to hold them away from each other for a distanceslightly greater than the thickness of said fixed contact finger locatedbetween them, said spring supports having a permanent deformationcausing them to bias said contact operator in a particular directioncausing its spacer portion to hold one of said movable contact fingersaway from said fixed contact finger but allowing the other of saidmovable contact fingers to rest against said movable contact fingerwholly free of any connection with said contact operator, a stop memberfor limiting the movement in said particular plane of said contactoperator by the bias of its supporting springs; electromagnetic meanshaving a pivoted armature operable to either of two extreme positionsbut cooperating with said contact operators in a manner to be normallybiased by them to a mid-position, said armature acting when operatedtoward either extreme position to actuate one of said contact operators,whereby a movable contact finger of each pair is normally making contactwith its respective fixed contact finger While said armature is in amid-position.

4. A circuit controlling contact mechanism comprising, a block ofinsulating material, a relatively rigid contact finger mounted on saidblock, two relatively fiexible movable contact fingers mounted on saidblock and positioned one on each side of said rigid contact finger, acontact operator of insulating material, two spring supports for saidcontact operator each mounted on said block, a stop member mounted onsaid block for limiting the movement of said spring supports and saidcontact operator in one direction, said two relatively flexible movablecontact fingers being biased toward said relatively rigid contact fingerwith a predetermined pressure, said two spring ill supports and saidcontact operator being biased toward said stop member with apredetermined pressure, said spring support bias being greater than saidmovable contact finger bias, said contact operator having a spacerportion located between the free end portions of said two relativelyflexible movable contact fingers, said spacer portion having a lengthgreater than the thickness of said relatively rigid contact finger toprevent both of said two relatively flexible movable contacts fromcontacting said relatively rigid contact finger at the same time,whereby an applied force against said contact operator in a directionreverse to said spring support bias will first move the normally closedflexible contact away from said rigid contact finger and next allow thenormally open flexible contact finger to bias itself closed against saidrigid contact finger, whereupon removal of said applied force will allowthe bias of said spring supports to return said contact operator andsaid two flexible contact fingers to their normal position.

5. In a clay organization, an electromagnetic core structure having acooperating pivoted armature operable from a normal mid-position toeither of two extreme positions by selective energization of windings onsaid core structure, said armature being limited in movement to its twoextreme positions and having means attached thereto for transmitting itsmovement to a contact operator, said contact operator being suspended ontwo spring fingers and having a notch therein forming two shoulders, twospaced rigid contact fingers each having a permanent magnet mountedthereon in a manner to face each other, a movable contact fingerpositioned between said two rigid contact fingers and having a magneticdisc mounted on each side thereof to cooperate with said two permanentmagnets, said movable contact finger having two resilient fingersmounted on its opposite sides at its free end which resilient fingerscooperate with said two shoulders on said contact operator but arelimited in their bending by said movable contact finger, whereby amovement of said armature in a given direction away from its midpositionwill cause said contact operator to force a magnetic break between saidmovable contact finger and one of said rigid contact fingers and allowsaid movable contact finger to make a magnetic connection with saidother rigid contact finger, said contact fingers having contact elementsthereon which cooperate with each other.

6. In combination a contact block having two fixed contact fingersmounted thereon at spaced locations, a movable contact finger locatedbetween said two fixed contact fingers and carrying a small circularmagnetic disc on each side thereof, said movable contact finger having afree end extending beyond said metal discs and having a spring member oneach side of such free end also extending at a slight angle to a lengthsubstantially correspondin with the free end of said movable contactfinger, ttvo small circular permanent magnets each mounted on itsrespective one of said two fixed contact fingers for cooperatin withsaid discs mounted on said movable contact finger, a contact operator ofinsulating material having a slotted portion into which the threeextending portions of said movable contact finger may be inserted, saidslot being greater than the distance between the ends of said springs onsaid movable contact finger but effective when moved in one direction tocause said magnetic discs to be drawn away from the permanent magnet onthe xed contact finger on its side only when such spring has lcen rfpressed to the extent that sufficient trapped pressure is present toovercome the magnetic pull of said permanent magnet, whereby saidmovable contact finger is quickly snapped to the opposite position whenit has been moved to a point beyond the central position between saidtwo fixed permanent magnets, in which opposite position it is held bysaid other permanent magnet.

7. A circuit controlling contact mechanism for operation by a push-puilmovement comprising, a block of insulating material, two rigid contactfingers mounted on said block, a flexible movable contact finger mountedon said block and positioned between said two rigid contact fingers, twoflexible spring supports mounted on said block, a contact operatormounted on and positioned between the free ends of said two springsupports, said flexible movable contact finger having a spaced resilientspring finger on each side of its free end and a magnetic disc on eachside near its center portion and a rivet of suitable contact materialfor holding together said flexible movable contact finger, saidresilient spring fingers and said magnetic discs; said two rigid contactfingers each having a small round permanent magnet fastened thereto bymeans of a bolt of suitable contact material, said permanent magnetsbeing located so as to face and co-act with its respective magnetic discon said flexible movable contact finger, said contact operator having aslotted portion which confines the free ends of said flexible movablecontact finger and its associated resilient spring fingers, said slottedportion of said contact operator having a width slightly greater thanthe span of said spaced resilient spring fingers lus the length of saidcontact operator travel during a movement from its center position to anextreme position; whereby a movement of said contact operator in adirection opposite to its last operated position will cause a shoulderof said slotted portion to compress its co-acting said resilient springfinger until sutflcient trapped pressure is available to overcome themagnetic pull of its associated said permanent magnet, whereupon saidflexible movable contact finger will break connection with one of saidrigid contact fingers and by a spring type snap action will be forcedinto a contacting position with the other of said rigid contact fingers,the magnetic pull of said other permanent magnet holding said flexiblemovable contact finger in a contacting position against said other rigidcontact finger until a reverse movement of said contact operator isstarted and proceeds beyond its center position.

8. In a relay organization, an electromagnetic core structure having aback yoke and a plurality of cores fastened thereto, two of said coreshaving an enlarged pole piece and a winding thereon, a pivoted armaturemounted between said two cores and operable to either of two extremepositions, said armature having means associated therewith for openingand closing contact fingers, each of said two cores having an adjustablestop bolt mounted therein and positioned to have one end facing saidarmature, said armature having two nonmagnetic residual pins mountedtherein and positioned so that each will cooperate with a separate oneof said stop bolts ends upon alternate movements of said armature, saidstop bolt ends having an insert of resilient fibrous material mountedtherein in such a manner 11; to rest against a shoulder and form an airpocket in the rear thereof, whereby an impact against said re"- insertwill be cushioned by said air pocket and said re ient insertcombination.

9. in a relay organiaztion, an electromagnetic structure having acooperating armature pivotally mounted between two pole shoes andoperable eith r of two extreme positions by selective cncrgizaticn ofwindings on said core structure, an adjustable stop bolt mounted in eachof said two pole shoes positioned t; have their ends cooperate withnonmagnetic residual pins in said armature when said arm .rc is ineither of its two extreme positions, said stop bolt ends being hollowedout and having an insert of resilient fibrous material mounted thereinin such a as to red against a shoulder and form an air pocke the rearthereof, said armature having centrally treated attached thereto fortransmitting its movement to u contact operator operably connected tosaid arm. s id contact operator eing suspended on two spring fingers andhaving a notch therein forming two shoulders, two spaced rigid contactfingers each having a permanent magnet mounted thereon in a manner toface each other, a movable contact finger positioned between said tworigid contact fingers and having a magnetic disc mounted on each sidethereof to cooperate with said two permanent magnets, said movablecontact finger having two resilient fingers mounted at its free endthereof which cooperate with said two shoulders on said contactoperator, whereby a movement of said armature in a given direction willcause said contact operator to force a magnetic break between saidmovable contact finger and one of said rigid contact fingers and allowsaid movable contact finger to make a magnetic connection with saidother rigid contact finger, said contact finger having contact elementsthereon which cooperate with each other, whereupon the impact of saidarmature against said stop bolt will be cushioned by said air pocket andsaid resilient insert combination.

References Cited in the file of this patent UNITED STATES PATENTSMallett June 12, 1888 Coleman July 5, 1904 Hobbs Feb. 14, 1911 LevisonSept. 14, 1915 Speed Oct. 24, 1916 Leake Apr. 5, 1932 Howe Nov. 1, 1938Field Nov. 8, 1938 McNairy Dec. 23, 1941 Cox Dec. 24, 1946 Ayers et a1.Jan. 6, 1948 Knapp et al. Oct. 1, 1957 FOREIGN PATENTS Austria Aug. 10,1915 Switzerland Dec. 16, 1953

